A thermoplastic elastomer material and its preparation method and application

Abstract

This application discloses a thermoplastic elastomer material, its preparation method, and its application, belonging to the field of polymer materials. By adding a polar elastomer to a SEBS material, controlling the ratio of the melt index of the polar elastomer to the melt index of the SEBS and plasticizer mixture within an appropriate range, and selecting a suitable compatibilizer, this application improves the bonding strength of the material to PC, ABS, and PC / ABS alloys. The resulting thermoplastic elastomer material is suitable for use in the production of automotive wireless charging panel encapsulation, audio floor mats, and other products.

Description

Technical Field

[0001] The present invention relates to the field of polymer materials, and in particular to a thermoplastic elastomer material and its preparation method and application. Background Art

[0002] In the automotive and electronics industries, PC (polycarbonate) and ABS (acrylonitrile-butadiene-styrene terpolymer) are widely used due to their excellent overall performance. As demand for product aesthetics and user experience continues to rise, an increasing number of PC and ABS parts are being coated with thermoplastic elastomers (TPEs), such as in automotive wireless charging panels and audio floor mats. This coating structure is typically achieved by directly injecting the TPE onto the surface of the PC, ABS, or PC / ABS alloy part through insert molding or two-shot molding. To prevent the TPE from detaching from the surface of the PC, ABS, or PC / ABS alloy part, good adhesion between the TPE and the PC, ABS, or PC / ABS alloy is essential.

[0003] PC, ABS and PC / ABS alloys have certain polarity and poor compatibility with common TPE materials (such as hydrogenated styrene-butadiene copolymer SEBS), resulting in poor adhesion of TPE materials on PC, ABS and PC / ABS alloys. Therefore, it is urgent to develop a technology to improve the adhesion of TPE materials to PC, ABS and PC / ABS alloys. Summary of the Invention

[0004] Based on the defects of the existing technology, the purpose of this application is to provide a thermoplastic elastomer material and its preparation method and application. The obtained thermoplastic elastomer material has high bonding strength and good bonding effect on PC, ABS and PC / ABS alloy.

[0005] In order to achieve the above objectives, in a first aspect, the present application provides a thermoplastic elastomer material comprising the following components in parts by weight: 24 to 36 parts of a hydrogenated styrene-butadiene copolymer, 30 to 50 parts of a polar elastomer, 3 to 5 parts of a compatibilizer, 25 to 35 parts of a plasticizer, 0 to 20 parts of a filler, and 0 to 2 parts of an additive;

[0006] The thermoplastic elastomer material satisfies: 10≤A / B≤30,

[0007] Wherein, A is the melt index of the polar elastomer at 190°C and 2.16 kg, in g / 10 min;

[0008] B is the melt index of the mixture obtained by mixing the hydrogenated styrene-butadiene copolymer and the plasticizer according to their proportions in the thermoplastic elastomer material at 190° C. and 2.16 kg, in units of g / 10 min.

[0009] The inventors have discovered that adding a polar elastomer to SEBS can improve its compatibility with PC and ABS, thereby enhancing its bonding strength to PC, ABS, and PC / ABS alloys. Controlling the ratio of the melt index of the polar elastomer to the melt index of the mixture of SEBS and plasticizer (i.e., A / B) in the formula within the aforementioned suitable range can promote the migration of the polar elastomer in the thermoplastic elastomer material to the bonding interface during the injection molding process, while avoiding significant phase separation between the polar elastomer and SEBS, ensuring that the thermoplastic elastomer material itself has good mechanical properties, and preventing the thermoplastic elastomer material from breaking during the bonding strength test, thereby improving the bonding strength of the thermoplastic elastomer material to PC, ABS, and PC / ABS alloys.

[0010] The SEBS content is 24 to 36 parts by weight, such as 24 parts by weight, 25 parts by weight, 26 parts by weight, 27 parts by weight, 28 parts by weight, 29 parts by weight, 30 parts by weight, 31 parts by weight, 32 parts by weight, 33 parts by weight, 34 parts by weight, 35 parts by weight, 36 parts by weight, or a range formed by any two of the above values. Preferably, the weight percentage of the SEBS in the thermoplastic elastomer material is greater than 15%, such as 15%, 18%, 20%, 22%, 24%, 26%, 28%, 30%, 32%, 34%, 36%, 38%, 38.3%, or a range formed by any two of the above values.

[0011] The polar elastomer is 30 to 50 parts by weight, such as 30 parts by weight, 32 parts by weight, 34 parts by weight, 36 parts by weight, 38 parts by weight, 40 parts by weight, 42 parts by weight, 44 parts by weight, 46 parts by weight, 48 parts by weight, 50 parts by weight or an interval formed by any two of the above values.

[0012] The compatibilizer is 3 to 5 parts by weight, such as 3 parts by weight, 3.2 parts by weight, 3.4 parts by weight, 3.6 parts by weight, 3.8 parts by weight, 4 parts by weight, 4.2 parts by weight, 4.4 parts by weight, 4.6 parts by weight, 4.8 parts by weight, 5 parts by weight or an interval formed by any two of the above values.

[0013] The plasticizer is 25 to 35 parts by weight, such as 25 parts by weight, 26 parts by weight, 27 parts by weight, 28 parts by weight, 29 parts by weight, 30 parts by weight, 31 parts by weight, 32 parts by weight, 33 parts by weight, 34 parts by weight, 35 parts by weight or an interval formed by any two of the above values.

[0014] The filler is 0 to 20 parts by weight, such as 0 parts by weight, 2 parts by weight, 4 parts by weight, 6 parts by weight, 8 parts by weight, 10 parts by weight, 12 parts by weight, 14 parts by weight, 16 parts by weight, 18 parts by weight, 20 parts by weight or an interval formed by any two of the above values.

[0015] The additive is 0 to 2 parts by weight, such as 0 parts by weight, 0.2 parts by weight, 0.4 parts by weight, 0.6 parts by weight, 0.8 parts by weight, 1 part by weight, 1.2 parts by weight, 1.4 parts by weight, 1.6 parts by weight, 1.8 parts by weight, 2 parts by weight or an interval formed by any two of the above values.

[0016] The A / B is 10-30, such as 10, 12, 14, 16, 18, 20, 22, 24, 26, 28, 30 or an interval formed by any two of the above values.

[0017] The A and the B are measured according to ASTM-D1238-2010.

[0018] Preferably, A is 9-16 g / 10 min, such as 9 g / 10 min, 10 g / 10 min, 11 g / 10 min, 12 g / 10 min, 13 g / 10 min, 14 g / 10 min, 15 g / 10 min, 16 g / 10 min or an interval formed by any two of the above values.

[0019] Preferably, B is 0.4-1.5 g / 10 min, such as 0.4 g / 10 min, 0.5 g / 10 min, 0.6 g / 10 min, 0.7 g / 10 min, 0.8 g / 10 min, 0.9 g / 10 min, 1.0 g / 10 min, 1.1 g / 10 min, 1.2 g / 10 min, 1.3 g / 10 min, 1.4 g / 10 min, 1.5 g / 10 min or an interval formed by any two of the above values.

[0020] The value of B can be controlled by adjusting the ratio of SEBS to plasticizer, the dynamic viscosity of SEBS in a toluene solution at 25° C. at a content of 10 wt.%, etc.

[0021] The ratio of the total weight of the hydrogenated styrene-butadiene copolymer and the plasticizer to the weight of the polar elastomer is 1 to 2.3, such as 1, 1.2, 1.4, 1.6, 1.8, 2, 2.2, 2.3, or any two of the above values. Preferably, the ratio of the total weight of the hydrogenated styrene-butadiene copolymer and the plasticizer to the weight of the polar elastomer is 1.2 to 1.8, so that the polar elastomer can achieve higher bonding strength on PC, ABS, and PC / ABS alloys at a lower addition amount relative to SEBS and the plasticizer, resulting in a higher cost-effectiveness.

[0022] Preferably, the SEBS has a styrene content of 20% to 40% by weight. For example, the SEBS has a styrene content of 20%, 22%, 24%, 26%, 28%, 30%, 32%, 34%, 36%, 38%, 40%, or a range formed by any two of these values. The styrene content in the SEBS is determined according to ASTM D5775-2019.

[0023] Preferably, the SEBS has a kinematic viscosity of 300-2000 cP at a 10 wt.% content in toluene solution at 25°C. For example, the hydrogenated styrene elastomer has a kinematic viscosity of 300 cP, 400 cP, 500 cP, 700 cP, 1000 cP, 1200 cP, 1500 cP, 1800 cP, 2000 cP, or a range formed by any two of the above values ​​at a 10 wt.% content in toluene solution at 25°C. The kinematic viscosity of the SEBS is measured according to ASTM D2196-2019.

[0024] Preferably, the polar elastomer includes at least one of thermoplastic polyurethane (TPU) and polyester elastomer (TPEE).

[0025] Preferably, the thermoplastic polyurethane includes at least one of thermoplastic polyester polyurethane and thermoplastic polyether polyurethane.

[0026] Preferably, the compatibilizer includes at least one of hydrogenated styrene-butadiene grafted maleic anhydride (SEBS-g-MAH) and POE grafted maleic anhydride (POE-g-MAH). Compared to POE-g-MAH, SEBS-g-MAH improves the bonding strength of thermoplastic elastomers to PC, ABS, and PC / ABS alloys.

[0027] Preferably, the grafting rate of maleic anhydride (i.e., MAH) in the hydrogenated styrene-butadiene copolymer grafted with maleic anhydride is 0.8 wt.% to 1.5 wt.%, such as 0.8 wt.%, 0.9 wt.%, 1.0 wt.%, 1.1 wt.%, 1.2 wt.%, 1.3 wt.%, 1.4 wt.%, 1.5 wt.%, or a range formed by any two of the above values.

[0028] Preferably, the maleic anhydride grafting rate in the POE-g-MAH is 1.0 wt.% to 1.5 wt.%, such as 1.0 wt.%, 1.1 wt.%, 1.2 wt.%, 1.3 wt.%, 1.4 wt.%, 1.5 wt.% or a range formed by any two of the above values.

[0029] The maleic anhydride grafting rate in the SEBS-g-MAH and the maleic anhydride grafting rate in the POE-g-MAH are measured according to the acid-base titration method. For example, a certain amount of SEBS-g-MAH or POE-g-MAH is accurately weighed and placed in a conical flask. An excess of a standard alkali solution is added and heated to completely neutralize the maleic anhydride on the grafted product. The excess alkali is then titrated out with a standard acid solution. The maleic anhydride content is calculated to obtain the grafting rate.

[0030] Preferably, the plasticizer is oil, and the oil includes at least one of white oil, paraffin oil, cycloparaffin oil and aromatic oil.

[0031] Preferably, the kinematic viscosity of the plasticizer at 40° C. is 30 to 45 mm² / s. For example, the kinematic viscosity of the plasticizer at 40° C. is 30 mm² / s, 32 mm² / s, 34 mm² / s, 36 mm² / s, 38 mm² / s, 40 mm² / s, or a range formed by any two of the above values.

[0032] The kinematic viscosity of the plasticizer is measured with reference to ASTM D445-2015.

[0033] Preferably, the filler includes at least one of calcium carbonate, talc and montmorillonite.

[0034] Preferably, the average particle size (ie, Dv50) of the filler is 50-300 nm. The average particle size of the filler is measured using a laser particle size analyzer.

[0035] Preferably, the auxiliary agent includes at least one of an antioxidant, a light stabilizer, and a lubricant.

[0036] Illustratively, the antioxidant includes at least one of antioxidant 1010 , antioxidant 1076 , and antioxidant 168 .

[0037] Exemplarily, the light stabilizer includes at least one of LA-402AF, UV-1600, and UV-3529.

[0038] The thermoplastic elastomer material may further comprise at least one of TPU and TPEE, such as 30 to 50 parts by weight of TPU and / or 30 to 50 parts by weight of TPEE.

[0039] In a second aspect, the present application provides a method for preparing the thermoplastic elastomer material, comprising the following steps:

[0040] All raw materials are mixed and dispersed, melt-extruded, and granulated to obtain a thermoplastic elastomer material.

[0041] Preferably, the temperature of the melt extrusion is 190-230°C.

[0042] Preferably, the melt extrusion is carried out in a twin-screw extruder, the aspect ratio of the twin-screw extruder is (36-60):1, and the screw speed is 300-400 r / min.

[0043] In a third aspect, the present application also provides the application of the thermoplastic elastomer material in the encapsulation of automobile wireless charging panels or audio foot pads.

[0044] In a fourth aspect, the present application further provides a rubber-coated product, comprising a base material and a coating material coated on the surface of the base material, wherein the coating material is the thermoplastic elastomer material.

[0045] Preferably, the matrix material includes at least one of PC and ABS.

[0046] Compared with the prior art, the present invention has the following advantages:

[0047] (1) The present application improves the bonding strength of SEBS materials on PC, ABS and PC / ABS alloys by adding polar elastomers to SEBS materials, controlling the ratio of the melt index of the polar elastomer in the formula to the melt index of the mixture of SEBS and plasticizer within an appropriate range, and selecting a suitable compatibilizer.

[0048] (2) The thermoplastic elastomer material of this application has high bonding strength on PC, ABS and PC / ABS alloy under the joint action of the specific contents of each component, and is suitable for preparing products such as automotive wireless charging panel encapsulation and audio foot pads. DETAILED DESCRIPTION

[0049] In order to better illustrate the purpose, technical solutions and advantages of the present application, the present application will be further described below in conjunction with specific embodiments and comparative examples. Its purpose is to understand the content of the present application in detail, rather than to limit the present application. All other embodiments obtained by those of ordinary skill in the art without making creative work are within the scope of protection of the present application. The experimental reagents and instruments involved in the implementation of this application are all commonly used ordinary reagents and instruments unless otherwise specified. In this application, the technical features described in an open manner include closed technical solutions composed of the listed features, and also include open technical solutions comprising the listed features.

[0050] Each of the following examples and comparative examples provides a thermoplastic elastomer material. The formulations of these thermoplastic elastomer materials are shown in Tables 1 and 2 (in the tables, (SEBS + plasticizer) / polar elastomer refers to the ratio of the total weight of the hydrogenated styrene-butadiene copolymer and the plasticizer to the weight of the polar elastomer). Their preparation methods include the following steps: mixing and dispersing all the raw materials, feeding them into a twin-screw extruder, melt-extruding, and granulating to obtain the thermoplastic elastomer material;

[0051] The screw length-diameter ratio of the twin-screw extruder is 48:1, the screw speed is 350 r / min, and the melt extrusion temperature is 200°C.

[0052] The raw materials used in the above examples and comparative examples are shown below. Unless otherwise specified, they are all commercially available raw materials. In addition, the components and raw materials used in each parallel experiment are the same:

[0053] SEBS 1: The dynamic viscosity of a 10 wt.% solution in toluene at 25°C is 400 cP, the styrene content is 31% by weight, model SEBS 7554, manufacturer Li Changrong;

[0054] SEBS 2: The dynamic viscosity of a 10 wt.% solution in toluene at 25°C is 1500 cP, and the styrene content is 33%. Model: YH-503, manufactured by Yuehua Chemical.

[0055] SEBS 3: 10 wt.% content in 25°C toluene solution has a dynamic viscosity of 2000 cP, styrene weight percentage 33%, model SEBS 7551, manufacturer Li Changrong;

[0056] Polar elastomer 1: TPU, model HY-185A, manufacturer Haoyi;

[0057] Polar elastomer 2: TPU, model 680AS-3, manufacturer Lianjing;

[0058] Polar elastomer 3: TPU, model HF-85AE, manufacturer Huafeng;

[0059] Polar elastomer 4: TPEE, model H28DFE, manufacturer Hechuang;

[0060] Compatibilizer 1: SEBS-g-MAH, MAH grafting rate 1.0wt.%, GPM5601, Ningbo Nengzhiguang;

[0061] Compatibilizer 2: POE-g-MAH, MAH grafting rate 1.0wt.%, model W1A, manufacturer Coase;

[0062] Plasticizer 1: white oil, kinematic viscosity at 40°C: 31.5 mm² / s, model 150N, manufactured by Formosa Plastics.

[0063] Plasticizer 2: paraffin oil, kinematic viscosity at 40°C is 43 mm² / s, model PW-32, manufactured by Illuminator;

[0064] Filler: calcium carbonate, commercially available;

[0065] Additives: antioxidant 1010 and antioxidant 168, the mass ratio of the two is 1:1, commercially available.

[0066] The melt index (i.e., A) values ​​of polar elastomers 1 to 4 at 190°C and 2.16 kg are shown in Tables 1 and 2. The following performance tests were conducted on the SEBS and plasticizer raw materials used in the above examples and comparative examples, as well as the resulting thermoplastic elastomer materials:

[0067] (1) The SEBS and plasticizer used were put into a high-speed mixer (25°C, 800 rpm, 15 min) according to their proportions in the thermoplastic elastomer material to mix and disperse to obtain a mixture of SEBS and plasticizer. The melt index of the mixture was tested at 190°C and 2.16 kg according to ASTM-D1238-2010.

[0068] (2) The obtained thermoplastic elastomer material was injection molded onto the surface of ABS (model KF-730, manufacturer Liaoning Jinfa) or PC (model PC 2220, manufacturer Wanhua Chemical) at a temperature of 200°C. After being placed at 23°C for 48 hours, a 90° peel test was performed at 23°C according to GB / T 7760-2003.

[0069] The test results are shown in Tables 1 and 2.

[0070] Table 1

[0071]

[0072] Table 2

[0073]

[0074] It can be seen from the above data that the thermoplastic elastomer materials in each embodiment of the present application have good bonding effect on ABS and PC and high bonding strength, such as the peel force on ABS is above 4.1N / mm, and the peel force on PC is above 4.2N / mm.

[0075] In Comparative Examples 1 to 4, the A / B values ​​are too low or too large, resulting in low bonding strength of the obtained thermoplastic elastomer materials on ABS and PC.

[0076] From the comparison of Examples 1 and 11 to 14, it can be seen that when the ratio of the total weight of the hydrogenated styrene-butadiene copolymer and the plasticizer to the weight of the polar elastomer is 1.2 to 1.8, the polar elastomer can achieve higher bonding strength on PC, ABS and PC / ABS alloy at a lower addition amount relative to SEBS and the plasticizer, and has a higher cost-effectiveness.

[0077] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application and are not intended to limit the scope of protection of the present application. Although the present application has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present application may be modified or replaced by equivalents without departing from the essence and scope of the technical solutions of the present application.

Claims

1. A thermoplastic elastomer material, characterized in that: The invention comprises the following components in parts by weight: 24-36 parts of a hydrogenated styrene-butadiene copolymer, 30-50 parts of a polar elastomer, 3-5 parts of a compatibilizer, 25-35 parts of a plasticizer, 0-20 parts of a filler, and 0-2 parts of an additive, wherein the weight percentage of styrene in the hydrogenated styrene-butadiene copolymer is 20%-40%, and the polar elastomer comprises at least one of a thermoplastic polyurethane and a polyester elastomer; The thermoplastic elastomer material satisfies: 10≤A / B≤30, Wherein, A is the melt index of the polar elastomer at 190°C and 2.16 kg, in g / 10 min; B is the melt index of the mixture obtained by mixing the hydrogenated styrene-butadiene copolymer and the plasticizer according to their proportions in the thermoplastic elastomer material at 190° C. and 2.16 kg, in g / 10 min; The A is 9-16 g / 10 min, and the B is 0.4-1.5 g / 10 min.

2. The thermoplastic elastomer material according to claim 1, characterized in that The ratio of the total weight of the hydrogenated styrene-butadiene copolymer and the plasticizer to the weight of the polar elastomer is 1.2-1.

8.

3. The thermoplastic elastomer material according to claim 1, characterized in that The hydrogenated styrene-butadiene copolymer has a dynamic viscosity of 300-2000 cP in a toluene solution at 25° C. at a content of 10 wt.%.

4. The thermoplastic elastomer material according to claim 1, characterized in that The plasticizer is oil, and the oil includes at least one of white oil, paraffin oil, cycloparaffin oil and aromatic oil; and / or The compatibilizer comprises at least one of a hydrogenated copolymer of styrene-butadiene grafted with maleic anhydride and a POE grafted with maleic anhydride; and / or The filler comprises at least one of calcium carbonate, talc and montmorillonite; and / or The auxiliary agent includes at least one of an antioxidant and a light stabilizer.

5. The method for preparing a thermoplastic elastomer material according to any one of claims 1 to 4, wherein: The following steps are involved: All raw materials are mixed and dispersed, melt-extruded, and granulated to obtain a thermoplastic elastomer material.

6. Use of the thermoplastic elastomer material according to any one of claims 1 to 4 in the encapsulation of automotive wireless charging panels or audio foot pads.

7. A plastic encapsulated product, characterized in that: It comprises a base material and a coating material coated on the surface of the base material, wherein the coating material is the thermoplastic elastomer material according to any one of claims 1 to 4.

8. The encapsulated product according to claim 7, characterized in that: The matrix material includes at least one of PC and ABS.

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